A model reads a book as another sleeps before presenting creations by Chinese designer Zhang Zhifeng from NE-TIGER's Spring/Summer 2013 collection at China Fashion Week in Beijing October 25, 2012. (Photo by Jason Lee/Reuters)

A cleaner sleeps while sitting on a chair at the Beijing West railway station October 28, 2012. (Photo by David Gray/Reuters)

A man sleeps as a woman walks past an entrance to a subway station at an underground passage in central Beijing, June 4, 2013. (Photo by Barry Huang/Reuters)

Children sleep on the floor of the Qiaosi subway station in Hangzhou, Zhejiang province July 25, 2013. More than 600 people cooled off inside the subway station as temperatures in the city hit a high of 40 degrees Centigrade during a regional power outage on Thursday. (Photo by Reuters/Stringer)

A vendor selling pork sleeps while still holding onto her knife at a market in Beijing September 7, 2012. (Photo by David Gray/Reuters)

A garbage collector sleeps on a couch on the edge of a hilly road in Lijiang, Yunnan province, August 2, 2013. (Photo by Reuters/Stringer)

An ethnic Uighur man takes a nap on a board as his sheep, which is tied to the board, stands next to him at a demolition site in Aksu, Xinjiang Uighur Autonomous Region August 13, 2012. (Photo by Reuters/Stringer)

A man takes a nap in the back of his cycle cart at the gate of the Tayuan Diplomatic Office Building in Beijing October 27, 2012. (Photo by Petar Kujundzic/Reuters)

Labourers who work nearby nap on a road as cars drive past in Chongqing Municipality, July 23, 2013. (Photo by Reuters/Stringer)

A vendor sleeps on packs of grapefruit at a market in Wuhan, Hubei province, October 15, 2012. (Photo by Reuters)

A laborer rests on piles of plastic bottles at a recycling center in Jiaxing, Zhejiang province November 6, 2011. (Photo by Reuters)

People take a nap on a street in Beijing July 4, 2013. (Photo by Kim Kyung-Hoon/Reuters)